Answer:
What is flat, usually square, and made from trees but isn't wood?
When one does not know what it is, then it is somethingอพ but when one knows what it is, then it is nothing.
A toy that requires some string and a breezy day
A white field, and when it is plowed, its soil is black.
What has to be broken before you can use it?
The sun bakes them, The hand breaks them, The foot treads on them, And the mouth tastes them. What are they?